The present invention relates generally to an improved pressure control and unloader valve and to the combination of such a valve with a high pressure diaphragm pump.
In contrast to the prior art, the present invention includes an improved pressure control and unloader valve usable for controlling the output pressure of a pump in the event that the discharge end of such pump is shut off or restricted. The improved unloader valve of the present invention includes means utilizing a water hammer and a floating check valve to open the unloader valve quickly as soon as the discharge end is shut off and to keep the unloader valve open for recirculation of the fluid being pumped until the discharge end is again opened. A present invention also includes the combination of such a pressure control valve with a diaphragm pump.
Accordingly, an object of the present invention is to provide an improved pressure control and unloader valve in which the unloader valve is controlled by the differential pressure between the pressure at the outlet of the pumping chamber of a pump with which such valve is used and atmospheric pressure.
A further object of the present invention is to provide an improved pressure control and unloader valve which utilizes a water hammer to open and keep open an elongated valve upon sudden shut off of the discharge end of the outlet passage.
Another object of the present invention is to provide a pressure control and unloader valve which includes a floating check valve.
A further object of the present invention is to provide an improved combination pressure control valve and diaphragm pump.
These and other objects of the present invention will become apparent upon reference to the drawings, the description of the preferred embodiment, and the appended claims.